minimal_macosx need to run on the 1st thread to be able to use video output

modules/gui/minimal_macosx/intf.m

@@ -63,6 +63,7 @@ int E_(OpenIntf) ( vlc_object_t *p_this )
     memset( p_intf->p_sys, 0, sizeof( *p_intf->p_sys ) );
 
     p_intf->pf_run = Run;
+    p_intf->b_should_run_on_first_thread = VLC_TRUE;
 
     return VLC_SUCCESS;
 }